Hydraulic tool fluid reservoir



im. 26, i943 M LEE HYDRAULIC TooL FLUIDy RESERVOIR Filed July 3l, 1940INVENTOR Wmv/N .55

Illini I r 1 f r r f r a l f l l n l,

ATTORNEY.

Patented Jan. 26, 1943 HYDRAULIC TOOL FLUID RESERVOIR Marvin Lee, Rye,N. Y., assignor to Burndy Engineering Company, Inc., a corporation ofNew York Application July 31, 1940, serial No. 349,023

(cl. zzo-ss) t 3 Claims.

This invention relates to uid reservoirs for use on hydraulicallyactuated mechanisms of the type illustrated in application filed August13, 1938, Ser. No. 224,820 for a Portable hydraulic press, by IrvingFrederick Matthysse.

Ordinarily a hydraulic tool which must be perated in any-position isequipped with a cylindrical iluid reservoir in which a follow-up pistonIfits snugly. This piston has packing placed about its diameter in orderto seal it in the-cylindrical reservoir. The fit of the packing must besnug enough to prevent fluid or air leakage past the piston but at thesame time, the piston must be able to move freely. As the fluid ispumped from the reservoir into the pressure chamber, atmosphericpressure forces the piston into the reservoir, taking up the space ofthe displaced oil. As a practical matter, however, atmospheric pressureis usually insufficient to overcome the friction of the packing againstthe cylinder walls and a follow-up spring is necessary/to assist inmoving the follow-up piston forward. The action of this spring is toapply a constant force against the follow-up piston which in turnapplies pressure against the hydraulic fluid even when the tool is notoperating. As a consequence of constant pressure on the fluid, some ofthe fluid is forced past the piston packing in a slow leakage. Thisleakage is insignificant for short periods of time but for extendedperiods may be very detrimental and may ultimately cause the tool tobecome inoperative.

One object of my invention, therefore, is to permit the hydraulicmechanism to be operated in any position without danger of air gettinginto the hydraulic system.

Another object of my invention is to eliminate the so-called follow-uppiston and packings.

Still another object of my invention is to provide an easy means ofaccess to the hydraulic system so that fluid may be readily introducedtherein without danger of air getting into the system.

A further object of myl invention is to protion, particularly pointedout in the attached vide all the foregoing advantages at low cost sinceit does not require the extremely'careful polishing and close tolerancesthat a cylindrical reservoir and follow-up piston require.

Another object is to eliminate friction and wear of moving parts, whichultimately may cause replacement of packings, refinishing of cylinderwalls, etc.

I accomplish these and other objects and obtain my new results as willbe apparent from claims, and illustrated in the accompanying drawing, inwhich:

Fig. 1A illustrates a side view of a form of hydraulic press.

Fig. 2 illustrates a sectional view of the reservoir or receptacle madeof a rubber compound.

Fig. 3 illustrates a sectional view of the reservoir or receptaclehaving contracting metal Walls.

Referring more particularly to the drawing, reference numeral I 0designates a portable press, illustrated in Fig. 1, with integral handleIl, pivoted lever I2, body I3, and a head I4, all

shown in cross section in co-pending application` Ser. No. 224,820.

Threadedly engaging the body I3 is the reservoir cap I5 within which iscontained, as shown in Fig. 2, a flexible container, receptacle or sackI6, made of resilient materia1 preferably a rubber-like compound thatcan withstand oil, such as neoprene.

At the mouth of the sack, adjacent the orifices I1 and I8, a metal ringI9 is preferably molded integrally therewith. Thus the rim 20 of the`molded material which covers the inner and contact face of the ring,acts as a gasket when the sack is clamped to the body I3 by rotating thereservoir cap l5 thereon.

The'other end of the sack I6, is molded into a tubular section 2l,withmetal spout 22 integrally bonded or otherwise attached thereto, toform a sealed joint. 'This spout is used to fill the sack with hydraulicuid and is capped by a closure 23. The spout may be provided with atexternal side walls 24, for use with a wrench to insure a tight fitbetween spout and closure.

The integral handle I I is provided with threaded section 25, which.engages an internally threaded section 26 of the reservoir cap I5.

As the handle I2 is osclllated towards handle II in a scissors-likeaction, a piston, not shown,

p pumps the iiuidfrom the sack I6 into the pressure chamber not shown,through orice Il. If the overload is reached, or'the release valve ofthe press is actuated, as described in the copending application Ser.No'. 224,820, the iluid is returned to the reservoir I6 through oriflceI8.

'I'he follow-up effect of the piston previously used in the reservoir isthus obtained by the use of the collapsible rubber sack. preventingl airfrom entering the hydraulic system. .A similar effect may be obtained bythe use of the to the body I3,

flexible metal bellows 30, shownin Fig. 3. Here the ring 3| is attachedto the rim $2 of the bellows, and the reservoir cap I5 seals the bellowspreventing leakage.

The remaining end of the bellows is formed into a tubular section 33,terminating in a closure 34.

As the oil is pumped from the bellows 30, the external air pressurecauses the bellows to contract to take up -the loss in volume, and atthe same time prevents the air from entering the oil chamber.

If sufllcient air does not leak in through the an inner collapsiblechamber provided with an opening at one end thereof in communicationthreaded section of the handle Il, a small ap- A erture 35, may beprovided, to permit the atmospheric pressure to operate the collapsibleoil reservoir inside the reservoir cap l5.

In the operation of my invention, using a neoprene sack, I have causedthe sack to be collapsed and refilled more than 5000 times without anysign of wear or deterioration.

I have thus described my invention, but I desire it understood that itis not conned to the particular forms or uses shown and described, thesame being merely illustrative, Vand that the invention may be carriedout in other ways without departing from the spirit of my invention,and, therefore, I claim broadly the right to employ all equivalentinstrumentalities coming within the scope of the appended claims, and bymeans of which, objects of my invention are attained and new resultsaccomplished, as it is obvious that the particular embodiments hereinshown and described are only some of the many that can be employed toattain these objects and accomplish these resu1ts.

What I claim and desire to secure by Letters Patent, is as follows:

1. A container for attachment to a supporting structure having anorifice therein, comprising a rigid outer wall with an opening at oneend thereof, and means for rigid attachment of the outer wall to thesupporting structure with the orifice and the opening in communication,said outer wall provided with an aperture at the remaining end thereof;and an inner collapsible chamber provided with an opening at one endthereof in communication with the orifice of the supporting structure,the other end of said chamber having an aperture and closure therefor incommunication with the aperture in the outer wall, that portion of thechamber containing the aperture and closure therefor being freely withthe orifice of the supporting structure, said collapsible chamber beingmade of rubber. and having a metal ring bonded to said chamber about theopening thereof to permit the outer wall to compress the bonded metalring to the supporting structure when the outer wall is threadedthereto, the other end of said chamber having an aperture and closuretherefor in communication with the aperture in the outer wall,

Athat portion of the chamber containing the aperture and closuretherefor being freely movable within the rigid outer wall whereby thechamber may be completely collapsed within the rigid outer wall underatmospheric pressure.

3. A container for attachment to a supporting structure having anorifice therein, comprising a rigid outer wall with an opening at oneend thereof, and means for rigid attachment of the outer wall to thesupporting structure with the orifice and the opening in communication,said outer wall provided with an aperture at the remaining end thereof;and an inner collapsible chamber provided with an opening at one endthereof in communication with the orice of the supporting structure, theother end of said chamber having an aperture and closure therefor incommunication with the aperture in the outer wall, the aperture in theouter wall being provided with an extending hollow closure within whichthe closure for the aperture of the flexible chamber is freely movable,and providing access to the closure for the exiblechamber upon removalof the extending closure of the outer wall, that portion of the chambercontaining the aperture and closure therefor being freely movable withinthe rigid outer wall and closure therefor whereby the chamber may becompletely collapsed Within the rigid outer wall under atmosphericpressure.

MARVIN LEE.

